Pandemics
A pandemic (from Greek πᾶν pan "all" + δῆμος demos "people") is an epidemic of infectious disease that has spread through human populations across a large region; for instance multiple continents, or even worldwide. A widespread endemic disease that is stable in terms of how many people are getting sick from it is not a pandemic. Further, flu pandemics generally exclude recurrences of seasonal flu. Throughout history there have been a number of pandemics, such as smallpox and tuberculosis. More recent pandemics include the HIV pandemic and the H1N1 pandemic. " pandemic resulted in dramatic mortality worldwide]] Definition and stages The World Health Organization (WHO) produce a six-stage classification that describes the process by which a novel influenza virus moves from the first few infections in humans through to a pandemic. This starts with the virus mostly infecting animals, with a few cases where animals infect people, then moves through the stage where the virus begins to spread directly between people, and ends with a pandemic when infections from the new virus have spread worldwide.Current WHO phase of pandemic alert World Health Organization 2009 A disease or condition is not a pandemic merely because it is widespread or kills many people;it must also be infectious. For instance, cancer is responsible for many deaths but is not considered a pandemic because the disease is not infectious or contagious. In a virtual press conference in May 2009 on the influenza pandemic Dr Keiji Fukuda, Assistant Director-General ad Interim for Health Security and Environment, WHO said "An easy way to think about pandemic ... is to say: a pandemic is a global outbreak. Then you might ask yourself: “What is a global outbreak”? Global outbreak means that we see both spread of the agent ... and then we see disease activities in addition to the spread of the virus." In planning for a possible influenza pandemic the WHO published a document on pandemic preparedness guidance in 1999, revised in 2005 and in February 2009, defining phases and appropriate actions for each phase in an aide memoir entitled WHO pandemic phase descriptions and main actions by phase. The 2009 revision, including definitions of a pandemic and the phases leading to its declaration, were finalized in February 2009. The pandemic H1N1 2009 virus, was neither on the horizon at that time nor mentioned in the document WHO pandemic phase descriptions and main actions by phase All versions of this document refer to influenza. The phases are defined by the spread of the disease; virulence and mortality are not mentioned in the current WHO definition, although these factors have previously been included. Current pandemics HIV and AIDS HIV spread to the United States and much of the rest of the world beginning around 1969.The virus reached the U.S. by way of Haiti, genetic study shows.. Los Angeles Times. October 30, 2007. HIV, the virus that causes AIDS, is currently a pandemic, with infection rates as high as 25% in southern and eastern Africa. In 2006 the HIV prevalence rate among pregnant women in South Africa was 29.1%. Effective education about safer sexual practices and bloodborne infection precautions training have helped to slow down infection rates in several African countries sponsoring national education programs. Infection rates are rising again in Asia and the Americas. AIDS could kill 31 million people in India and 18 million in China by 2025, according to projections by U.N. population researchers.AIDS Toll May Reach 100 Million in Africa. Washington Post. June 4, 2006. AIDS death toll in Africa may reach 90–100 million by 2025. Pandemics and notable epidemics through history There have been a number of significant pandemics recorded in human history, generally zoonoses which came about with domestication of animals, such as influenza and tuberculosis. There have been a number of particularly significant epidemics that deserve mention above the "mere" destruction of cities: * Plague of Athens, 430 BC. Typhoid fever killed a quarter of the Athenian troops, and a quarter of the population over four years. This disease fatally weakened the dominance of Athens, but the sheer virulence of the disease prevented its wider spread; i.e. it killed off its hosts at a rate faster than they could spread it. The exact cause of the plague was unknown for many years. In January 2006, researchers from the University of Athens analyzed teeth recovered from a mass grave underneath the city, and confirmed the presence of bacteria responsible for typhoid."Ancient Athenian Plague Proves to Be Typhoid". Scientific American. January 25, 2006. in Martigues, France]] * Antonine Plague, 165–180. Possibly smallpox brought to the Italian peninsula by soldiers returning from the Near East; it killed a quarter of those infected, and up to five million in all.Past pandemics that ravaged Europe. BBC News, November 7. 2005 At the height of a second outbreak, the Plague of Cyprian (251–266), which may have been the same disease, 5,000 people a day were said to be dying in Rome. * Plague of Justinian, from 541 to 750, was the first recorded outbreak of the bubonic plague. It started in Egypt, and reached Constantinople the following spring, killing (according to the Byzantine chronicler Procopius) 10,000 a day at its height, and perhaps 40% of the city's inhabitants. The plague went on to eliminate a quarter to a half of the human population that it struck throughout the known world. Quotes from book "Plague and the End of Antiquity" Lester K. Little, ed., Plague and the End of Antiquity: The Pandemic of 541–750, Cambridge, 2006. ISBN 0-521-84639-0 It caused Europe's population to drop by around 50% between 550 and 700. * Black Death, started 14th century. The total number of deaths worldwide is estimated at 75 million people.New MOL Archaeology monograph: Black Death cemetery. Archaeology at the Museum of London. Eight hundred years after the last outbreak, the plague returned to Europe. Starting in Asia, the disease reached Mediterranean and western Europe in 1348 (possibly from Italian merchants fleeing fighting in the Crimea), and killed an estimated 20 to 30 million Europeans in six years;Death on a Grand Scale. MedHunters. a third of the total population,Stéphane Barry and Norbert Gualde, in L'Histoire n° 310, June 2006, pp.45–46, say "between one-third and two-thirds"; Robert Gottfried (1983). "Black Death" in Dictionary of the Middle Ages, volume 2, pp.257–67, says "between 25 and 45 percent". and up to a half in the worst-affected urban areas.Plague – LoveToKnow 1911. 1911encyclopedia.org. It was the first of a cycle of European plague epidemics that continued until the 18th century. During this period, more than 100 plague epidemics swept across Europe. In England, for example, epidemics would continue in two to five-year cycles from 1361 to 1480. By the 1370s, England's population was reduced by 50%. The Great Plague of London of 1665–66 was the last major outbreak of the plague in England. The disease killed approximately 100,000 people, 20% of London's population.The Great Plague of London, 1665. The Harvard University Library, Open Collections Program: Contagion. * Third Pandemic, started in China in the middle of the 19th century, spreading plague to all inhabited continents and killing 10 million people in India alone.Plague. World Health Organization. During this pandemic, the United States saw its first outbreak: the San Francisco plague of 1900–1904.Bubonic plague hits San Francisco 1900 – 1909. A Science Odyssey. Public Broadcasting Service (PBS). Today, isolated cases of plague are still found in the western United States.Human Plague – United States, 1993–1994, Centers for Disease Control and Prevention '' (compiled 1540–1585)]] Encounters between European explorers and populations in the rest of the world often introduced local epidemics of extraordinary virulence. Disease killed part of the native population of the Canary Islands in the 16th century (Guanches). Half the native population of Hispaniola in 1518 was killed by smallpox. Smallpox also ravaged Mexico in the 1520s, killing 150,000 in Tenochtitlán alone, including the emperor, and Peru in the 1530s, aiding the European conquerors. Measles killed a further two million Mexican natives in the 17th century. In 1618–1619, smallpox wiped out 90% of the Massachusetts Bay Native Americans.Smallpox The Fight to Eradicate a Global Scourge, David A. Koplow During the 1770s, smallpox killed at least 30% of the Pacific Northwest Native Americans.Greg Lange,"Smallpox epidemic ravages Native Americans on the northwest coast of North America in the 1770s", 23 Jan 2003, HistoryLink.org, Online Encyclopedia of Washington State History, accessed 2 Jun 2008 Smallpox epidemics in 1780–1782 and 1837–1838 brought devastation and drastic depopulation among the Plains Indians. Some believe that the death of up to 95% of the Native American population of the New World was caused by Old World diseases such as smallpox, measles, and influenza. Over the centuries, the Europeans had developed high degrees of immunity to these diseases, while the indigenous peoples had no such immunity.Stacy Goodling, "Effects of European Diseases on the Inhabitants of the New World" Smallpox devastated the native population of Australia, killing around 50% of Indigenous Australians in the early years of British colonisation.Smallpox Through History It also killed many New Zealand Māori. As late as 1848–49, as many as 40,000 out of 150,000 Hawaiians are estimated to have died of measles, whooping cough and influenza. Introduced diseases, notably smallpox, nearly wiped out the native population of Easter Island.How did Easter Island's ancient statues lead to the destruction of an entire ecosystem?, The Independent In 1875, measles killed over 40,000 Fijians, approximately one-third of the population.Fiji School of Medicine The disease devastated the Andamanese population.Measles hits rare Andaman tribe. BBC News. May 16, 2006. Ainu population decreased drastically in the 19th century, due in large part to infectious diseases brought by Japanese settlers pouring into Hokkaido.Meeting the First Inhabitants, TIMEasia.com, 21 August 2000 Researchers concluded that syphilis was carried from the New World to Europe after Columbus' voyages. The findings suggested Europeans could have carried the nonvenereal tropical bacteria home, where the organisms may have mutated into a more deadly form in the different conditions of Europe.Genetic Study Bolsters Columbus Link to Syphilis, New York Times, January 15, 2008 The disease was more frequently fatal than it is today. Syphilis was a major killer in Europe during the Renaissance.Columbus May Have Brought Syphilis to Europe, LiveScience Between 1602 and 1796, the Dutch East India Company sent almost a million Europeans to work in the Asia. Ultimately, only less than one-third made their way back to Europe. The majority died of diseases.Nomination VOC archives for Memory of the World Register (English) Disease killed more British soldiers in India than war. Between 1736 and 1834 only some 10% of East India Company's officers survived to take the final voyage home. As early as 1803, the Spanish Crown organized a mission (the Balmis expedition) to transport the smallpox vaccine to the Spanish colonies, and establish mass vaccination programs there.Dr. Francisco de Balmis and his Mission of Mercy, Society of Philippine Health History By 1832, the federal government of the United States established a smallpox vaccination program for Native Americans. From the beginning of the 20th century onwards, the elimination or control of disease in tropical countries became a driving force for all colonial powers.Conquest and Disease or Colonialism and Health?, Gresham College | Lectures and Events The sleeping sickness epidemic in Africa was arrested due to mobile teams systematically screening millions of people at risk. In the 20th century, the world saw the biggest increase in its population in human history due to lessening of the mortality rate in many countries due to medical advances.The Origins of African Population Growth, by John Iliffe, The Journal of African HistoryVol. 30, No. 1 (1989), pp. 165–169 The world population has grown from 1.6 billion in 1900 to an estimated 7 billion today. Cholera From a local disease, cholera became one of the most widespread and deadly diseases of the 19th century, killing tens of millions of people..Kelley Lee (2003) "Health impacts of globalization: towards global governance". Palgrave Macmillan. p.131. ISBN 0-333-80254-3 * First cholera pandemic 1816–1826. Previously restricted to the Indian subcontinent, the pandemic began in Bengal, then spread across India by 1820. 10,000 British troops and countless Indians died during this pandemic. It extended as far as China, Indonesia (where more than 100,000 people succumbed on the island of Java alone) and the Caspian Sea before receding. Deaths in India between 1817 and 1860 are estimated to have exceeded 15 million persons. Another 23 million died between 1865 and 1917. Russian deaths during a similar period exceeded 2 million. * Second cholera pandemic 1829–1851. Reached Russia (see Cholera Riots), Hungary (about 100,000 deaths) and Germany in 1831, London in 1832 (more than 55,000 persons died in the United Kingdom), France, Canada (Ontario), and United States (New York) in the same year, and the Pacific coast of North America by 1834. A two-year outbreak began in England and Wales in 1848 and claimed 52,000 lives.Cholera's seven pandemics, cbc.ca, December 2, 2008 It is believed that over 150,000 Americans died of cholera between 1832 and 1849.The 1832 Cholera Epidemic in New York State – Page 2. By G. William Beardslee * Third pandemic 1852–1860. Mainly affected Russia, with over a million deaths. In 1852, cholera spread east to Indonesia and later invaded China and Japan in 1854. The Philippines were infected in 1858 and Korea in 1859. In 1859, an outbreak in Bengal again led to the transmission of the disease to Iran, Iraq, Arabia and Russia.Asiatic Cholera Pandemic of 1846–63 . UCLA School of Public Health. Throughout Spain, cholera caused more than 236,000 deaths in 1854–55. It claimed 200,000 lives in Mexico. * Fourth pandemic 1863–1875. Spread mostly in Europe and Africa. At least 30,000 of the 90,000 Mecca pilgrims fell victim to the disease. Cholera claimed 90,000 lives in Russia in 1866. * In 1866, there was an outbreak in North America. It killed some 50,000 Americans. * Fifth pandemic 1881–1896. The 1883–1887 epidemic cost 250,000 lives in Europe and at least 50,000 in Americas. Cholera claimed 267,890 lives in Russia (1892); 120,000 in Spain; 90,000 in Japan and 60,000 in Persia. * In 1892, cholera contaminated the water supply of Hamburg, and caused 8606 deaths. * Sixth pandemic 1899–1923. Had little effect in Europe because of advances in public health, but Russia was badly affected again (more than 500,000 people dying of cholera during the first quarter of the 20th century).cholera :: Seven pandemics, Britannica Online Encyclopedia The sixth pandemic killed more than 800,000 in India. The 1902–1904 cholera epidemic claimed over 200,000 lives in the Philippines.John M. Gates, Ch. 3, "The U.S. Army and Irregular Warfare" 27 epidemics were recorded during pilgrimages to Mecca from the 19th century to 1930, and more than 20,000 pilgrims died of cholera during the 1907–08 hajj.Cholera (pathology). Britannica Online Encyclopedia. * Seventh pandemic 1962–66. Began in Indonesia, called El Tor after the strain, and reached Bangladesh in 1963, India in 1964, and the USSR in 1966. Influenza influenza pandemic alert phases]] * The Greek physician Hippocrates, the "Father of Medicine", first described influenza in 412 BCE.50 Years of Influenza Surveillance. World Health Organization. * The first influenza pandemic was recorded in 1580 and since then influenza pandemics occurred every 10 to 30 years."Pandemic Flu". Department of Health and Social Security.Beveridge, W.I.B. (1977) Influenza: The Last Great Plague: An Unfinished Story of Discovery, New York: Prodist. ISBN 0-88202-118-4. * The "Asiatic Flu", 1889–1890, was first reported in May 1889 in Bukhara, Uzbekistan. By October, it had reached Tomsk and the Caucasus. It rapidly spread west and hit North America in December 1889, South America in February–April 1890, India in February–March 1890, and Australia in March–April 1890. It was purportedly caused by the H2N8 type of flu virus. It had a very high attack and mortality rate. About 1 million people died in this pandemic."CIDRAP article Pandemic Influenza Last updated 29 May 2008 * The "Spanish flu", 1918–1919. First identified early in March 1918 in US troops training at Camp Funston, Kansas. By October 1918, it had spread to become a worldwide pandemic on all continents, and eventually infected about one-third of the world's population (or ≈500 million persons). Unusually deadly and virulent, it ended nearly as quickly as it began, vanishing completely within 18 months. In six months, some 50 million were dead; some estimates put the total of those killed worldwide at over twice that number.Spanish flu, ScienceDaily About 17 million died in India, 675,000 in the United StatesThe Great Pandemic: The United States in 1918–1919, U.S. Department of Health & Human Services. and 200,000 in the UK. The virus was recently reconstructed by scientists at the CDC studying remains preserved by the Alaskan permafrost. The H1N1 virus has a small, but crucial structure that is similar to the Spanish Flu.http://www.scientificamerican.com/blog/post.cfm?id=h1n1-shares-key-similar-structures-2010-03-24 * The "Asian Flu", 1957–58. An H2N2 virus caused about 70,000 deaths in the United States. First identified in China in late February 1957, the Asian flu spread to the United States by June 1957. It caused about 2 million deaths globally.Q&A: Swine flu. BBC News. April 27, 2009. * The "Hong Kong Flu", 1968–69. An H3N2 caused about 34,000 deaths in the United States. This virus was first detected in Hong Kong in early 1968, and spread to the United States later that year. This pandemic of 1968 and 1969 killed approximately one million people worldwide. Influenza A (H3N2) viruses still circulate today. Typhus Typhus is sometimes called "camp fever" because of its pattern of flaring up in times of strife. (It is also known as "gaol fever" and "ship fever", for its habits of spreading wildly in cramped quarters, such as jails and ships.) Emerging during the Crusades, it had its first impact in Europe in 1489, in Spain. During fighting between the Christian Spaniards and the Muslims in Granada, the Spanish lost 3,000 to war casualties, and 20,000 to typhus. In 1528, the French lost 18,000 troops in Italy, and lost supremacy in Italy to the Spanish. In 1542, 30,000 soldiers died of typhus while fighting the Ottomans in the Balkans. During the Thirty Years' War (1618–1648), about 8 million Germans were killed by bubonic plague and typhus fever.War and Pestilence. TIME. April 29, 1940 The disease also played a major role in the destruction of Napoleon's Grande Armée in Russia in 1812. Felix Markham thinks that 450,000 soldiers crossed the Neman on 25 June 1812, of whom less than 40,000 recrossed in anything like a recognizable military formation.See a large copy of the chart here: http://www.adept-plm.com/Newsletter/NapoleonsMarch.htm, but discussed at length in Edward Tufte, The Visual Display of Quantitative Information (London: Graphics Press, 1992) In early 1813 Napoleon raised a new army of 500,000 to replace his Russian losses. In the campaign of that year over 219,000 of Napoleon's soldiers were to die of typhus. Typhus played a major factor in the Irish Potato Famine. During World War I, typhus epidemics killed over 150,000 in Serbia. There were about 25 million infections and 3 million deaths from epidemic typhus in Russia from 1918 to 1922. Typhus also killed numerous prisoners in the Nazi concentration camps and Soviet prisoner of war camps during World War II. More than 3.5 million Soviet POWs died in the Nazi custody out of 5.7 million.Soviet Prisoners of War: Forgotten Nazi Victims of World War II By Jonathan Nor, TheHistoryNet Smallpox Smallpox is a highly contagious disease caused by the Variola virus. The disease killed an estimated 400,000 Europeans per year during the closing years of the 18th century.Smallpox and Vaccinia. National Center for Biotechnology Information. During the 20th century, it is estimated that smallpox was responsible for 300–500 million deaths. How Poxviruses Such As Smallpox Evade The Immune System, ScienceDaily, February 1, 2008 As recently as early 1950s an estimated 50 million cases of smallpox occurred in the world each year."Smallpox". WHO Factsheet. Retrieved on 2007-09-22. After successful vaccination campaigns throughout the 19th and 20th centuries, the WHO certified the eradication of smallpox in December 1979. To this day, smallpox is the only human infectious disease to have been completely eradicated. Measles Historically, measles was prevalent throughout the world, as it is highly contagious. According to the National Immunization Program, 90% of people were infected with measles by age 15. Before the vaccine was introduced in 1963, there were an estimated 3–4 million cases in the U.S. each year.Center for Disease Control & National Immunization Program. Measles History, article online 2001. Available from http://www.cdc.gov.nip/diseases/measles/history.htm In roughly the last 150 years, measles has been estimated to have killed about 200 million people worldwide. In 2000 alone, measles killed some 777,000 worldwide. There were some 40 million cases of measles globally that year. Measles is an endemic disease, meaning that it has been continually present in a community, and many people develop resistance. In populations that have not been exposed to measles, exposure to a new disease can be devastating. In 1529, a measles outbreak in Cuba killed two-thirds of the natives who had previously survived smallpox.Man and Microbes: Disease and Plagues in History and Modern Times; by Arno Karlen The disease had ravaged Mexico, Central America, and the Inca civilization."Measles and Small Pox as an Allied Army of the Conquistadors of America" by Carlos Ruvalcaba, translated by Theresa M. Betz in "Encounters" (Double Issue No. 5-6, pp. 44–45) Tuberculosis One–third of the world's current population has been infected with Mycobacterium tuberculosis, and new infections occur at a rate of one per second.World Health Organization (WHO). Tuberculosis Fact sheet N°104 – Global and regional incidence. March 2006, Retrieved on 6 October 2006. About 5–10% of these latent infections will eventually progress to active disease, which, if left untreated, kills more than half of its victims. Annually, 8 million people become ill with tuberculosis, and 2 million people die from the disease worldwide.Centers for Disease Control. Fact Sheet: Tuberculosis in the United States. 17 March 2005, Retrieved on 6 October 2006. In the 19th century, tuberculosis killed an estimated one-quarter of the adult population of Europe;Multidrug-Resistant Tuberculosis. Centers for Disease Control and Prevention. by 1918 one in six deaths in France were still caused by TB. By the late 19th century, 70 to 90% of the urban populations of Europe and North America were infected with M. tuberculosis, and about 40% of working-class deaths in cities were from TB.Tuberculosis in Europe and North America, 1800–1922. The Harvard University Library, Open Collections Program: Contagion. During the 20th century, tuberculosis killed approximately 100 million people. TB is still one of the most important health problems in the developing world.Immune responses to tuberculosis in developing countries: implications for new vaccines. Nature Reviews Immunology 5, 661–667 (August 2005). Leprosy Leprosy, also known as Wopat’s or Hansen's Disease, is caused by a bacillus, Mycobacterium leprae. It is a chronic disease with an incubation period of up to five years. Since 1985, 15 million people worldwide have been cured of leprosy.Leprosy 'could pose new threat'. BBC News. April 3, 2007. In 2002, 763,917 new cases were detected. It is estimated that there are between one and two million people permanently disabled because of leprosy.Leprosy (Hansen's Disease).Centers for Disease Control and Prevention (CDC). Historically, leprosy has affected people since at least 600 BCE, and was well recognized in the civilizations of ancient China, Egypt and India. During the High Middle Ages, Western Europe witnessed an unprecedented outbreak of leprosy."Medieval leprosy reconsidered". International Social Science Review, Spring-Summer, 2006, by Timothy S. Miller, Rachel Smith-Savage. Numerous leprosaria, or leper hospitals, sprang up in the Middle Ages; Matthew Paris estimated that in the early 13th century there were 19,000 across Europe. Malaria Malaria is widespread in tropical and subtropical regions, including parts of the Americas, Asia, and Africa. Each year, there are approximately 350–500 million cases of malaria.Malaria Facts. Centers for Disease Control and Prevention. Drug resistance poses a growing problem in the treatment of malaria in the 21st century, since resistance is now common against all classes of antimalarial drugs, except for the artemisinins. Malaria was once common in most of Europe and North America, where it is now for all purposes non-existent.Vector- and Rodent-Borne Diseases in Europe and North America. Norman G. Gratz. World Health Organization, Geneva. Malaria may have contributed to the decline of the Roman Empire.DNA clues to malaria in ancient Rome. BBC News. February 20, 2001. The disease became known as "Roman fever"."Malaria and Rome". Robert Sallares. ABC.net.au. January 29, 2003. Plasmodium falciparum became a real threat to colonists and indigenous people alike when it was introduced into the Americas along with the slave trade. Malaria devastated the Jamestown colony and regularly ravaged the South and Midwest. By 1830 it had reached the Pacific Northwest."The Changing World of Pacific Northwest Indians". Center for the Study of the Pacific Northwest, University of Washington. During the American Civil War, there were over 1.2 million cases of malaria among soldiers of both sides. The southern U.S. continued to be afflicted with millions of cases of malaria into the 1930s.Malaria. By Michael Finkel. National Geographic Magazine. Yellow fever Yellow fever has been a source of several devastating epidemics.Yellow Fever – LoveToKnow 1911. Cities as far north as New York, Philadelphia, and Boston were hit with epidemics. In 1793, one of the largest yellow fever epidemics in U.S. history killed as many as 5,000 people in Philadelphia—roughly 10% of the population. About half of the residents had fled the city, including President George Washington. Approximately 300,000 people are believed to have died from yellow fever in Spain during the 19th century.Tiger mosquitoes and the history of yellow fever and dengue in Spain. In colonial times, West Africa became known as "the white man's grave" because of malaria and yellow fever.Africa's Nations Start to Be TheirBrothers' Keepers. The New York Times, October 15, 1995. Unknown causes There are also a number of unknown diseases that were extremely serious but have now vanished, so the etiology of these diseases cannot be established. The cause of English Sweat in 16th-century England, which struck people down in an instant and was more greatly feared than even the bubonic plague, is still unknown. Concern about possible future pandemics Viral hemorrhagic fevers Some Viral Hemorrhagic Fever causing agents like Lassa fever virus, Rift Valley fever, Marburg virus, Ebola virus and Bolivian hemorrhagic fever are highly contagious and deadly diseases, with the theoretical potential to become pandemics. Their ability to spread efficiently enough to cause a pandemic is limited, however, as transmission of these viruses requires close contact with the infected vector, and the vector only has a short time before death or serious illness. Furthermore, the short time between a vector becoming infectious and the onset of symptoms allows medical professionals to quickly quarantine vectors, and prevent them from carrying the pathogen elsewhere. Genetic mutations could occur, which could elevate their potential for causing widespread harm; thus close observation by contagious disease specialists is merited. Antibiotic resistance Antibiotic-resistant microorganisms, sometimes referred to as "superbugs", may contribute to the re-emergence of diseases which are currently well controlled.Researchers sound the alarm: the multidrug resistance of the plague bacillus could spread. Pasteur.fr For example, cases of tuberculosis that are resistant to traditionally effective treatments remain a cause of great concern to health professionals. Every year, nearly half a million new cases of multidrug-resistant tuberculosis (MDR-TB) are estimated to occur worldwide.Health ministers to accelerate efforts against drug-resistant TB. World Health Organization. China and India have the highest rate of multidrug-resistant TB.Bill Gates joins Chinese government in tackling TB 'timebomb'. Guardian.co.uk. April 1, 2009 The World Health Organization (WHO) reports that approximately 50 million people worldwide are infected with MDR TB, with 79 percent of those cases resistant to three or more antibiotics. In 2005, 124 cases of MDR TB were reported in the United States. Extensively drug-resistant tuberculosis (XDR TB) was identified in Africa in 2006, and subsequently discovered to exist in 49 countries, including the United States. There are about 40,000 new cases of XDR-TB per year, the WHO estimates.Tuberculosis: A new pandemic?. CNN.com In the past 20 years, common bacteria including Staphylococcus aureus, Serratia marcescens and Enterococcus, have developed resistance to various antibiotics such as vancomycin, as well as whole classes of antibiotics, such as the aminoglycosides and cephalosporins. Antibiotic-resistant organisms have become an important cause of healthcare-associated (nosocomial) infections (HAI). In addition, infections caused by community-acquired strains of methicillin-resistant Staphylococcus aureus (MRSA) in otherwise healthy individuals have become more frequent in recent years. Inappropriate antibiotic treatment and overuse of antibiotics have been an element in the emergence of resistant bacteria. The problem is further exacerbated by self-prescribing of antibiotics by individuals without the guidelines of a qualified clinician and the non-therapeutic use of antibiotics as growth promoters in agriculture. SARS In 2003, there were concerns that Severe Acute Respiratory Syndrome (SARS), a new and highly contagious form of atypical pneumonia, might become pandemic. It is caused by a coronavirus dubbed SARS-CoV. Rapid action by national and international health authorities such as the World Health Organization helped to slow transmission and eventually broke the chain of transmission. That ended the localized epidemics before they could become a pandemic. However, the disease has not been eradicated. It could re-emerge. This warrants monitoring and reporting of suspicious cases of atypical pneumonia. Influenza Wild aquatic birds are the natural hosts for a range of influenza A viruses. Occasionally, viruses are transmitted from these species to other species, and may then cause outbreaks in domestic poultry or, rarely, in humans. H5N1 (Avian Flu) In February 2004, avian influenza virus was detected in birds in Vietnam, increasing fears of the emergence of new variant strains. It is feared that if the avian influenza virus combines with a human influenza virus (in a bird or a human), the new subtype created could be both highly contagious and highly lethal in humans. Such a subtype could cause a global influenza pandemic, similar to the Spanish Flu, or the lower mortality pandemics such as the Asian Flu and the Hong Kong Flu. From October 2004 to February 2005, some 3,700 test kits of the 1957 Asian Flu virus were accidentally spread around the world from a lab in the US. In May 2005, scientists urgently call nations to prepare for a global influenza pandemic that could strike as much as 20% of the world's population. In October 2005, cases of the avian flu (the deadly strain H5N1) were identified in Turkey. EU Health Commissioner Markos Kyprianou said: "We have received now confirmation that the virus found in Turkey is an avian flu H5N1 virus. There is a direct relationship with viruses found in Russia, Mongolia and China." Cases of bird flu were also identified shortly thereafter in Romania, and then Greece. Possible cases of the virus have also been found in Croatia, Bulgaria and the United Kingdom. By November 2007, numerous confirmed cases of the H5N1 strain had been identified across Europe. However, by the end of October only 59 people had died as a result of H5N1 which was atypical of previous influenza pandemics. Avian flu cannot yet be categorized as a "pandemic", because the virus cannot yet cause sustained and efficient human-to-human transmission. Cases so far are recognized to have been transmitted from bird to human, but as of December 2006 there have been very few (if any) cases of proven human-to-human transmission.WHO (2005). Avian Influenza A (H5N1) Infection in Humans http://www.nejm.org/doi/full/10.1056/NEJMra052211 Regular influenza viruses establish infection by attaching to receptors in the throat and lungs, but the avian influenza virus can only attach to receptors located deep in the lungs of humans, requiring close, prolonged contact with infected patients, and thus limiting person-to-person transmission. Biological warfare In 1346, the bodies of Mongol warriors who had died of plague were thrown over the walls of the besieged Crimean city of Kaffa (now Theodosia). After a protracted siege, during which the Mongol army under Jani Beg was suffering the disease, they catapulted the infected corpses over the city walls to infect the inhabitants. It has been speculated that this operation may have been responsible for the arrival of the Black Death in Europe. The Native American population was devastated after contact with the Old World due to the introduction of many different fatal diseases. There is, however, only one documented case of germ warfare, involving British commander Jeffrey Amherst and Swiss-British officer Colonel Henry Bouquet, whose correspondence included a reference to the idea of giving smallpox-infected blankets to Indians as part of an incident known as Pontiac's Rebellion which occurred during the Siege of Fort Pitt (1763) late in the French and Indian War. It is uncertain whether this documented British attempt successfully infected the Indians.Dixon, Never Come to Peace, 152–55; McConnell, A Country Between, 195–96; Dowd, War under Heaven, 190. For historians who believe the attempt at infection was successful, see Nester, Haughty Conquerors", 112; Jennings, Empire of Fortune, 447–48. During the Sino-Japanese War (1937–1945), Unit 731 of the Imperial Japanese Army conducted human experimentation on thousands, mostly Chinese. In military campaigns, the Japanese army used biological weapons on Chinese soldiers and civilians. Plague fleas, infected clothing, and infected supplies encased in bombs were dropped on various targets. The resulting cholera, anthrax, and plague were estimated to have killed around 400,000 Chinese civilians. Diseases considered for or known to be used as a weapon include anthrax, ebola, Marburg virus, plague, cholera, typhus, Rocky Mountain spotted fever, tularemia, brucellosis, Q fever, machupo, Coccidioides mycosis, Glanders, Melioidosis, Shigella, Psittacosis, Japanese B encephalitis, Rift Valley fever, yellow fever, and smallpox. Spores of weaponized anthrax were accidentally released from a military facility near the Soviet closed city of Sverdlovsk in 1979. The Sverdlovsk anthrax leak is sometimes called "biological Chernobyl".Ken Alibek and S. Handelman. Biohazard: The Chilling True Story of the Largest Covert Biological Weapons Program in the World – Told from Inside by the Man Who Ran it. 1999. Delta (2000) ISBN 0-385-33496-6 http://www.amazon.com/dp/0385334966/. China possibly suffered a serious accident at one of its biological weapons plants in the late 1980s. The Soviets suspected that two separate epidemics of hemorrhagic fever that swept the region in the late 1980s were caused by an accident in a lab where Chinese scientists were weaponizing viral diseases.William J Broad, Soviet Defector Says China Had Accident at a Germ Plant, New York Times, April 5, 1999 In January 2009, an Al-Qaeda training camp in Algeria was reportedly wiped out by the plague, killing approximately 40 Islamic extremists. Some experts said that the group was developing biological weapons,Al-Qaeda cell killed by Black Death 'was developing biological weapons' Telegraph. January 20, 2009. however, a couple of days later the Algerian Health Ministry flatly denied this rumour stating "No case of plague of any type has been recorded in any region of Algeria since 2003".Plague outbreak denied Feb. 5, 2009. See also * Biological hazard * Bioterrorism * Biological warfare * Centers for Disease Control and Prevention (CDC) * Epidemic * Endemic * European Centre for Disease Prevention and Control (ECDC) * Disease transmission * Globalization and disease * Influenza pandemic * Mortality from infectious diseases * Medieval demography * Panic * Risk assessment * Syndemic * Pandemic Severity Index * Tropical diseases * WHO pandemic phases References Notes Bibliography * Further reading * Steward's "The Next Global Threat: Pandemic Influenza". * American Lung Association. (2007, April), Multidrug Resistant Tuberculosis Fact Sheet. As retrieved from www.lungusa.org/site/pp.aspx?c=dvLUK9O0E&b=35815 November 29, 2007. * * External links * WHO – Authoritative source of information about global health issues * Past pandemics that ravaged Europe * CDC: Influenza Pandemic Phases * European Centre for Disease Prevention and Control – ECDC * The American Journal of Bioethics' ethical issues in pandemics page *TED-Education video – How pandemics spread. Category:Biological hazards * Category:Epidemiology Category:Infectious disorders * Category:Economic problems Category:Global health